In offshore drilling applications, oilfield tubulars (e.g., casing, drill pipe, strings thereof, etc.) are run from a drilling rig located on a marine vessel or a platform, down to the ocean floor, and then into an earthen bore formed in the ocean floor. In the case of the drilling rig being provided as a buoyant, marine vessel, the position of the vessel is affected by waves on the surface of the ocean. This position change is generally referred to as “heave.”
Rig vessels employ a variety of active and passive systems to limit heave; however, heaving movement of the vessel may still occur, for example, in rough seas. This may present a challenge, as the rig may support the oilfield tubular string deployed therefrom using a relatively rigid assembly, for example, including a spider, as compared to a hoisting assembly supporting the oilfield tubulars from flexible cables or compensating systems. Thus, when heaving movement of the rig occurs while the spider supports the oilfield tubular string, a force tending to move the upper end of the tubular string is applied thereto, while the inertia and/or other constraints applied to the position of the tubular string resist such movement. This represents a dynamic loading of the spider and/or the tubular string. Given the heavy weight of the tubular string and rig, such heave-induced dynamic loading may potentially reach dangerous levels.
What is needed are tubular support assemblies and methods for monitoring such dynamic loading so as to, for example, avoid damaging the rig structure or the tubular.